Patent Application
20100319891
The present invention relates to methods for producing a heat exchanger and also to heat exchangers produced according to said methods, emphasizing that said heat exchangers can be used in a particularly advantageous manner within the field of heat exchangers that use gaseous liquids, such as air or similar.
Heat exchangers exist that comprise a plurality of interconnecting banks each defining a fluid flow, each bank comprising at least two solid plates produced in an impervious material and kept at a spacing from one another by different types of spacing means.
However, the known exchangers of this type are relatively expensive and do not perform overly well, which has meant that they have not been able to reach a wider audience and be used in all types of technical areas, for example in the ventilation of residential buildings and/or industrial buildings and/or commercial buildings for the recovery of heat-energy conveyed, for example, using equipment known by the initials VMC.
For example, U.S. Pat. No. 5,287,918 is known, relating to a compact “fin-plate” heat exchanger and to a method for producing such an exchanger. The exchanger comprises, for example, three flat metal sheets, for example made in titanium, stacked one above the other, interconnected in a partial manner by means of an adhesive so as to allow the two outer sheets to be moved apart when a pressurized gas is introduced between the sheets. The intermediate sheet is produced in a super-plastic material which meets a precise technical definition that can be summed up by a material with a large plastic deformation phase at high temperature allowing for large elongation at break. Once the outside sheets have been moved apart, the intermediate sheet is deformed so as to define two liquid flow channels on both sides of said intermediate sheet, and between the two outside sheets of the stack, respectively.
US 2006/0070728 is also known and relates to a heat exchanger intended for a ventilation system for a structure so as to optimise the replacement of the inside air by the outside air. This document notably describes a conventional exchanger which includes a plurality of thin flat laminated plates between which are disposed respectively smooth pleated plates. The outside air passes between the pleats formed by a pleated plate between two flat plates, forming a bank of air flow, whilst the inside air passes between the pleats formed by the adjacent pleated plate of a similar adjacent bank. Two adjacent banks form two air flows, the inside flow and the outside flow respectively, in accordance with two senses of direction at 90°. The invention according to this document consists in replacing the smooth pleated plates by drilled pleated plated so as to increase the air turbulence when it flows through the exchanger, and thus to improve the output of this latter. In addition, the pleats can advantageously be disposed offset with regard to the direction of the air flow. The sheets of the exchanger can be produced in aluminium or paper and the intermediate drilled sheets can be produced in a porous resin film.
It is also an object of the present invention to implement a method for producing a heat exchanger which, at least to a great extent, alleviates the disadvantages referred to above of heat exchangers of the prior art.
More particularly, it is the object of the present invention to implement a method for producing a heat exchanger that weighs less than exchangers of the prior art, with reduced pressure loss in the fluid flows and costing less to produce, whilst at the same time improving heat exchanges between the banks, throwing off the dimensional restrictions imposed by the prior art and increasing resistance to pressure differences between the banks of fluid flow.
More precisely, the object of the present invention is a method for producing a heat exchanger comprising a plurality of interconnecting banks each defining a fluid flow, each bank comprising two solid plates, respectively the top plate and the bottom plate produced in an impervious material, and spacing means to keep the two solid plates at a spacing one from the other, characterized in that the production of at least one of the said banks includes the following steps:
(A) producing an insert plate comprising:
The object of the present invention is also a heat exchanger obtained with the method defined above.
Other characteristics and advantages of the invention will appear during the following description given with respect to the drawings provided for illustrative purposes only but being in no way restrictive, in which:
First of all it must be stated that in the Figures the same references designate the same elements, whatever the Figure on which they appear and whatever form of representation these elements may take. In the same way, if elements are not referenced specifically on one of the Figures, their references can be easily found by looking at another Figure.
It must also be stated that these Figures represent essentially one single embodiment of the object according to the invention, but there may be other embodiments that meet the definition of this invention.
It must also be stated that when, according to the definition of the invention, the object of the invention includes “at least one” element with a given function, the embodiment described can comprise a plurality of said elements. Reciprocally, if the embodiment of the object according to the invention such as is illustrated comprises a plurality of elements with an identical function and if, in the description, it is not specified that the object according to this invention must, in an obligatory manner, comprise a specific number of said elements, the object of the invention can be defined as comprising “at least one” of said elements.
Finally it must be stated that when, in the present description, one expression on its own, with no specific particular mention concerning it, defines a set of structural characteristics, these characteristics can be taken, for the definition of the object of the protection requested, when this is technically possible, either separately or in total and/or partial combination.
First of all it must be pointed out again, by referring to
The method according to the invention is characterized essentially in that the production of at least one of the banks 2, 3, 4 includes the five steps A to E defined below.
The first step A, more particularly with reference to
It must be noted that the insert plate 20 can be in the form of a draughtboard (not represented), the squares of one of the colours of the draughtboard would in fact be the openings and the squares of the other colour on the draughtboard would be produced from material, these latter being connected by corners constituting in this way notably the bridges of weakness described above. Thus, each of the strips 21, 22, 23 described above would be constituted on their respective edges by two alignments of discontinuous squares, defining the two lanes 31, 32 along the two longitudinal edges of the strip, these two discontinuous lanes 31, 32 being interconnected by an alignment of offset discontinuous squares defining the partition walls 28, 29 described above and therefore connecting the two lanes. According to this alternative embodiment, the two lanes 31, 32 and the partition walls 28, 29, forming a determined strip, and the two similar adjacent strips on both sides of the same, would be connected by the corners of the squares of the draughtboard constituted by material, and forming the bridges of weakness.
These bridges of weakness can be constituted in different ways, for example by tabs connecting the strips as illustrated in the Figures, or by one single continuous tab between two strips that can be obtained by producing a groove or a furrow in the intermediate plate 20, or also by joints in the material between two corners of two squares of a draughtboard as described above.
The second step B consists in interposing the insert plate 20, which has the characteristics defined above and is obtained during step A, between the two solid impervious plates, the top plate and the bottom plate, as illustrated in
A third step C consists in interposing the binding means 41, 42 between, on the one hand, the top face 33 of each left lane 31 of all the strips 21, 22, 23 and the bottom face 1-11 of the top plate 11, and, on the other hand, the bottom face 34-1 of each right lane 32 of all the strips 21, 22, 23 and the top face 1-12 of the bottom plate 12.
However, it is stipulated that said third step C can be executed before of after the first step A or after the second step B defined above, although, according to an advantageous characteristic of the method given below, this third step C is preferably executed before the first step A or before the second step B.
In
As for the fourth step D, it consists in applying a first force, indicated in
According to the nature of the binding means 41, 42, the stack of three plates may be submitted to adapted heating.
The fifth step E of the method is executed when the adherence between the lanes 31, 32 and the plates 11, 12 has been completely obtained. It consists, with reference to the schematic
In a preferred manner, to obtain a rigid heat exchanger that is not, for example, capable of vibrating and/or deforming notably by swelling when put into operation in the fluid flow, the method consists in parting the top plate and the bottom plate 11, 12 one from the other by applying a second force to them, until the partition walls 28, 29 between the openings form an angle approximately equal to ninety degrees with the two plates, the top plate and the bottom plate 11, 12.
At the end of executing the fifth step E, the heat exchanger is provided as schematically illustrated in the side view represented in
It must be noted that the two fold lines of the Z-shaped strips are obtained on the two imaginary lines 101, 102 represented by the broken lines that go through the two edges 51, 52 of the openings that delimit the left and right lanes 31, 32. These folds are promoted by the very existence of the openings and the small width and thickness of the partition walls 28, 29 between said openings. In fact, these two fold lines are made automatically when the second force is applied.
According to a preferred characteristic of the method, the openings 25, 26, 27 in each strip 21, 22, 23 are produced such that their edges 51, 52 referred to above are co-linear 102, 102 and parallel to the longitudinal axis of the lanes, with the aim of making folding into a Z-shape as defined above easier to accomplish.
The counter-current fluid flow between two juxtaposed banks is advantageously established in the direction of the two imaginary lines 101, 102 corresponding to the two fold lines of the Z-shaped strips, and between the adjusted strips 21, 22, 23. The width of the openings 25, 26, 27 of each strip 21, 22, 23 allows the flow of a fluid 5, 6 to be controlled such that it is rather channeled between the strips 21, 22, 23 of one bank when this width is small, or can also be distributed across the openings 25, 26, 27 of each strip 21, 22, 23, in a diverging manner, then a converging manner, between the entry 5en, 6en and the exit 5ex, 6ex of the fluid for each bank considered.
As represented in
It must be noted that, in a known manner, the counter-current character of the flow of the fluids between two adjacent banks, will be all the more efficient given that, with respect to
The method according to the invention is particularly interesting in terms of the goals to be obtained defined in the preamble of the present description, i.e. notably to obtain an exchanger that allows for very good heat exchanges whilst at the same time not being too expensive to produce and or being too heavy, as it is possible to use plates 11, 12, 20 that are approximately between thirty and a thousand microns thick, produced in materials such as aluminium, copper, aluminium-base alloys or copper-base alloys, or any other material that is a good heat conductor.
As for the binding means 41, 42, they can be of different types. However, they will preferably be selected from those that operate in accordance with at least one of the following functions: bonding, brazing, welding.
In addition, still with the aim of obtaining the lowest possible production cost, said binding means 41, 42 shall be selected from those that can be applied by seriography or by micro projection, for example flat, on at least one of the following elements: the top and bottom faces of the lanes 33, 34-1, the bottom face 1-11 of the top plate and the top face 1-12 of the bottom plate 12; it is well known that said application techniques can easily be applied in an automated manner.
With the same objective, the production of the openings 25, 2627 can be effected according to at least one of the following techniques: micro cutting, stamping, laser cutting, pressurized water jet spray which can easily be automated, chemical milling or electrochemical milling.
It has been mentioned, and can be seen in
This middle zone 60 without any openings, in spite of everything, can be edged at each of its ends by at least one opening 25-26 to constitute the entry and the exit of the bank,
It is also possible for at least one of the two lateral strips 21 not to have an openings, this allows, for example, a flow bank totally sealed on one side and partially on the other to be obtained, the entry and exit being on the same side in this embodiment.
Although, on
To facilitate bending the strips 21, 22, 23 into a Z-shape as defined above, the method consists in producing the openings 25-26 with one of the following forms: rectangular, square, triangular, trapezoidal, round, oval.
To avoid the appearance of tears in the intermediate plate 20 when adjusting the partition walls 28, 29, it is advantageous to produce the openings 25, 26, 27 with the edges not having any sharp rims following a direction at right angles to the plane of the intermediate plate 20. In the case, for example, of the possible forms mentioned above, it is advantageous for the openings to have rounded corners.
A method of implementing the method according to the invention has been described above to produce one of the banks of the heat exchanger according to the invention, but it is very clear that all the banks of a same exchanger can be produced in the same way, and at the same time, emphasizing that one of the two solid plates delimiting one bank is used as one of the two solid plates for the consecutive bank, and so on.
In this case, all the banks 2, 3, 4 will be produced at once. Such an embodiment is in the field of expertise of the expert who, having become familiar with the description given above, will know how to implement the method to produce an exchanger according to the invention with a plurality of banks. The implementation of the method to produce an exchanger according to the invention with a plurality of banks will therefore not be described in any more detail here purely with the aim of trying to simplify the present description.
In this case, however, as is illustrated schematically in
It is of course the same for all the insert plates 20. That is to say all the partition walls 28, 29 between the openings 25, 26, 27 of one bank will be respectively situated in the same plane as all the partition walls 28, 29 of all the other banks.
The exchanger 1, obtained in this manner, will be more resistant to pressure both outside and inside, with the partition walls 28, 29 one above the other aligned forming the individual spacer units for all the banks. These individual spacer units prevent, for example, the top and bottom plates 11, 12 from deforming at the ends of the partition walls 28, 29, which could occur if they were, for example, offset staggered in rows.
This advantageous configuration with a plurality of banks is illustrated schematically in
However, in an advantageous manner, the method can comprise a supplementary sixth step F which consists, after producing a plurality of interconnecting banks, in enclosing this plurality of banks 2, 3, 4 in a housing 70,
For reasons, for example, of integration in more complex systems, certain ends of the banks can be sealed by fixed or detachable plugs so as to facilitate cleaning of the same.
The present invention also relates to a heat exchanger 1 produced according to the method described above.
In the above description, it emerges that the method according to the invention for producing a heat exchanger is very economical as, apart from the fact that it can be implemented with little material, nearly all of the stages of the different steps can be easily automated, for example by using robots with grippers (no-load suction cups) notably to handle the plates 11, 12, 20, cutting robots and robots for applying the binding means 41, 42, functioning according to the techniques mentioned throughout the present description explaining the different steps of the implementation of the method according to the invention.
Finally, it must be stated and emphasized that, in terms of the present description, the adjectives “top” and “bottom”, “right” and “left” are only used to facilitate differentiation, purely with respect to the plane of the Figures, of the positions of the two solid plates 11, 12 one with respect to the other, the respective positions of the lanes 21, 32 of a same strip, and the respective faces of the lanes. In no way, for example, must the adjectives “top” and “bottom” be understood purely as defining a position of the horizontal plates 11, 12 at the respective levels in accordance with a vertical. These plates 11, 12 can be positioned according to any direction whatsoever with respect to the ground.
Translation on
| Number | Date | Country | Kind |
|---|---|---|---|
| 0701295 | Feb 2007 | FR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/FR2008/000237 | 2/22/2008 | WO | 00 | 8/21/2009 |
